Shaving unit for safety razor

ABSTRACT

The specific disclosure provides a shaving unit having two superimposed flexible double edge razor blades with the cutting edges of the top blades being set back a slight distance from the cutting edges of the bottom blade. An elongated slot extends through the blades for locating the shaving unit in a double edge safety razor. Means are provided between the aperture and the cutting edges to one side of the aperture for permanently connecting the blades together. The cutting edges to said one side of the aperture are spaced apart a predetermined distance, and the cutting edges to the other side are spaced apart a distance less than the predetermined distance when the razor blades are in an unflexed state.

[ June 17, 1975 I SHAVING UNIT FOR SAFETY RAZOR [75] Inventor: George W. Hale, III, Plymouth,

Conn.

[73] Assignee: Warner-Lambert Company, Morris Plains, NJ.

[22] Filed: Dec. 13, 1974 [21] Appl. No.: 532,428

[52] [1.8. CI 30/346.58; 30/50 [51] Int. Cl. B26B 21/54; B26B 21/22 [58] Field of Search ESQ/346.57, 346.58, 346.59,

30/50; 76/DIG. 6

[56] References Cited UNITED STATES PATENTS 3,262,206 7/1966 Tomek 30/346.59

FOREIGN PATENTS OR APPLICATIONS 1,103,671 11/1955 France 30/346.58

Primary Examiner-Al Lawrence Smith Assistant Examiner-Gary L. Smith Attorney, Agent, or Firm-James F. Powers, Jr.; Albert I-I. Graddis 5 7] ABSTRACT The specific disclosure provides a shaving unit having two superimposed flexible double edge razor blades with the cutting edges of the top blades being set back a slight distance from the cutting edges of the bottom blade. An elongated slot extends through the blades for locating the shaving unit in a double edge safety razor. Means are provided between the aperture and the cutting edges to one side of the aperture for permanently connecting the blades together. The cutting edges to said one side of the aperture are spaced apart a predetermined distance, and the cutting edges to the other side are spaced apart a distance less than the predetermined distance when the razor blades are in an unflexed state.

15 Claims, 4 Drawing Figures PATENTEDJUH 11 I975 3. 889,370 SHEET 1 1 SHAVING UNIT FOR SAFETY RAZOR BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to shaving units having a plurality of cutting edges for use in a safety razor. More particularly, the present invention relates to safety razor shaving units having a plurality of double cutting edge members bonded together.

2. Description of the Prior Art Double edge safety razors are well known in the art, and are in many forms. For example, U.S. Pat. Nos. 3,293,745, 3,466,746 and 3,708,879 disclose a razor having sectional caps, an adjustable razor and a razor having a hinged cap, respectively. Such razors act to clamp a thin, flexible double edge razor blade in the razor head with each cutting edge oriented with respect to a guard bar surface.

U.K. Pat. No. 772,532 discloses a shaving unit having two double edge razor blades which are vertically separated by a flexible spacer. The cutting edges of the top blade are set back a slight distance from the cutting edges of the bottom blade to provide tandemly arranged cutting edges on each side of the shaving unit.

U.l(. Pat. No. 772,532 contemplates welding the blades and spacer together, and, at Page 3, lines 98-100, specifically teaches welding the spacer near its elongated ends.

Commercially available flexible steel double edge razor blades having an elongated central slot parallel to the cutting edges are arcuately flexed at tab portions at each end of the slot when firmly seated in double edge razors having manually operated mechanisms for opening and closing the cap portion. However, as shown in FIG. 4 of U.S. Pat. No. 3,708,879, the portions of the razor blades between the slot and the cutting edges are substantially flat.

Welding metal increases grain size of the metal about the weld, and the corrosion rate about the weld is high. When double edge razor blades are welded together at the tab portions. and the tab portions are thereafter arcuately bent in a razor as specifically taught in U.K. Pat. No. 772,5 32, a danger of stress-corrosion cracking is raised. Stress-corrosion cracking is failure by cracking under combined corrosion and applied and/or residual stress.

SUMMARY OF THE INVENTION In accordance with a broad aspect of the present invention, there is provided a shaving unit for a double edge safety razor comprising a first flexible member having a pair of opposite cutting edge sides. A second flexible member also having a pair of opposite cutting edge sides is positioned above the first member with the cutting edges of the second member being set back a slight distance from the cutting edges of the first member. A transversely elongated aperture vertically extends through the shaving unit for locating the shaving unit in the safety razor. Means are provided between the aperture and the cutting edges on one side of the aperture for permanently connecting the first and second members together. The cutting edges to said one side of the aperture being spaced apart a predetermined distance, and the cutting edges to the other side of the aperture being spaced apart a distance less than the predetermined distance when the first and second members are in an unflexed state. However, when the shaving unit is seated in a double edge safety razor the cutting edges to said other side of the aperture are spaced apart at least approximately said predetermined distance.

A shaving unit constructed in accordance with the present invention minimizes the stress-corrosion cracking problem by bonding the components of the shaving unit at surfaces which are at least substantially flat when the unit is seated in the razor.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of an embodiment of a shaving unit constructed in accordance with the present invention;

FIG. 2 is a top plan view of the shaving unit of FIG. 1 with portions of the component parts of the shaving unit cut away;

FIG. 3 is a side elevational view of another embodiment of a shaving unit constructed in accordance with the present invention; and

FIG. 4 is a side cross-sectional view of the shaving unit of FIG. 1 seated in a sectional capped razor.

DESCRIPTION OF SPECIFIC EMBODIMENTS With reference to FIGS. 1 and 2, one representative embodiment of the present invention has first and second members 82, 81 in the form of double cutting edge razor blades, and means in the form of a spacer element 80 for vertically spacing the second member 81 from the first member 82. The blades 81, 82 and the spacer element 80 are permanently connected together by four welds 76 diagrammatically represented by dashed circles on one side of transversely elongated apertures 83-85 formed in the spacer element 80 and the blades 81, 82.

As clearly shown in FIG. 2, the cutting edges 88, 89 of the top blade 81 are set back a slight distance from the cutting edges 90, 91 of the bottom blade 82. However, the horizontal distance A between the cutting edges 89, 91 to the side 78 of the apertures 83-85 not having welds is less than the horizontal distance B between the cutting edges 88, 90 to the side 79 of the apertures having welds where the unit is in an unflexed state.

The cutting edges 88, 89 on opposite sides of the top blade are parallel to the cutting edges 90, 91 on opposite sides of the bottom blade 82. The spacer element 80 has a pair of blunt surfaces 86, 87 set back a slight distance from the cutting edges 88, 89 of the top blade 81. The apertures 83-85 extend between end tab portions 72, 73; 70, 71; 74, of the spacer element and the blades 81, 82.

FIG. 4 shows the shaving unit seated and clamped in a double edge safety razor having a center-bar and stem assembly 40. The center-bar and stem assembly 40 is fitted through the apertures 83-85 to locate the shaving unit in the razor. A pair of sectional caps 41, 42 act to bias the shaving unit on a blade seat with the cutting edges of the blades 81, 82 tandemly arranged with respect to guard bar surfaces 44, 45 formed on the outer ends of the blade seat.

FIG. 4 also shows the shaving unit portions 78, 79 between the tabs 70-75 in a flat state. However, the tab portions 7075 are arcuately bent (not shown). When the unit is thus seated in a razor the top blade shifts a slight distance to the right as viewed in FIG. 4 such that the distance A between the cutting edges 88, 91 to the side 78 not having welds is at least approximately equal to the distance B between the cutting edges to the side 79 having the welds.

The blades 81, 82 and the spacer element 80 can be composed of thin martensitic stainless steel commonly used for razor blades, or of any other flexible material suitable for double edge razor blades. The thickness of the blades 81, 82 and of the spacer 80 can be 0.0039 inches. The distance between the cutting edges of the top blade 81 can suitably be 0.8355 1*: 0.005 inches when the distance between the cutting edges of the bot tom blade is 0.870 t 0.005 inches. The distance between the blunt surfaces 86, 87 of the spacer element 80 can be 0.780 inches.

The horizontal distance B between the cutting edges 88, 90 can suitably be from about 0.016 inch to about 0.024 inch, and the horizontal distance A between the cutting edges 89, 91 when the unit in an unflexed state can suitable be from about 0.01 inch to about 0.0195 inch. The horizontal distances A, B may be selected within these ranges such that the linear distance between the cutting edges 88, 90; 89, 91 on each side 79, 78 of the unit is about 0.0176 inch to about 0.0254 inch when the unit is in a flexed state in a safety razor.

' The shaving unit can be welded anywhere on the flat shaving unit portion 79 between the tabs 71, 73, 75; 70, 72, 74, but sufficiently inwardly of the top blade cutting edges 88, 89 to avoid adversely affecting the cutting edges 88, 89. A suitable position for the welds is about 0.219 inch from the transverse center line of the unit.

FIG. 3 shows another embodiment of the present invention wherein'a pair of double edge 95, 96 blades are welded directly together. The distance between the cutting edges 99, 100 to the right of FIG. 3 are fixed by welding the unit between the transverse apertures (not shown) and these cutting edges 99, 100. The other cutting edges as free to float when being seated in a double edge razor as described hereinabove with reference to FIGS. 1, 2 and 4.

The components of shaving units can be bonded together by spot, projection, arc, laser or other welding techniques. The flat shaving unit portions 78, 79 can alternatively be bonded together by adhesives. Further, the spacer can be formed of a plastic material.

The embodiment shown in the figures has symmetrically beveled surfaces forming the cutting edges of the blades 81, 82. However, it is contemplated that the beveled cutting edge surfaces of one or both of the blades 81, 82 can be asymmetrically ground to increase the vertical distance between the cutting edges of the blades 81, 82. This alternative embodiment is particuments of two double edge blades bonded together on each side of the center apertures. The force needed to bend the shaving 'units of US. Pat. No. 3,851,392 is Y greater than that required to bend a shaving unit constructed in accordance with the present invention.

What is claimed is:

l. A shaving unit for a double edge safety razor, said shaving unit comprising:

a. a first flexible member including a pair of transversely extending opposite sides, each one of the first member opposite sides having a cutting edge, and a pair of spaced end tabs, each one of said tabs extending outwardly from an opposite end of said first member;

b. a second flexible member including a pair of transversely extending opposite sides, each one of the second member opposite sides having a cutting edge, and a pair of spaced end tabs, each one of said tabs extending outwardly from an opposite end of said second member, said second member being positioned above said first member with the cutting edges of said second member being positioned upwardly and inwardly of the cutting edges of said first member;

0. a transversely elongated aperture between said tabs of said first member and said second member and vertically extending through said shaving unit for locating said shaving unit in said safety razor; and

d. means between said aperture and the cutting edges to one side only of said aperture for permanently connecting said first member and said second member together;

e. the cutting edges to said one side of said aperture being spaced apart a predetermined distance, and the cutting edges to the other side of said aperture being spaced apart a distance less than said predetermined distance when said first and second members are in an unflexed state.

2. The shaving unit of claim 1 further comprising flexible means between said first member and said second member for vertically spacing said second member from said first member.

3. The shaving unit of claim 2 wherein said connecting means comprises means for bonding said spacing means to said first member and to said second member.

4. The shaving unit of claim 3 wherein the cutting edges of said first member and said second member are parallel.

5. The shaving unit of claim 4 wherein said first and second members are metallic members.

6. The shaving unit of claim 5 wherein said spacing means is a metallic component.

7. The shaving unit of claim 6 wherein said connecting means comprises a plurality of spot welds.

8. The shaving unit of claim 6 wherein said first and second members are double cutting edge safety razor blades.

9. The shaving unit of claim 1 wherein said connecting means comprises means for bonding said second member directly to said first member.

10. The shaving unit of claim 9 wherein the cutting edges of said first member and said second member are parallel.

11. The shaving unit of claim 10 wherein said first and second members are metallic members.

12. The shaving unit of claim 11 wherein said connecting means comprises a plurality of spot welds.

13. The shaving unit of claim 12 wherein said first and second members are double cutting edge safety razor blades.

3 ,8 89 ,3 70 5 6 1,4. The shaving unit of claim 1 wherein said first and aperture are spaced apart at least approximately said g members are double cuttmg edge Safety razor predetermined distance when said unit is seated in said a es.

15. The shaving unit of claim 1 wherein said tabs are curved and the cutting edges to said other side of said 5 double edge safety razor. 

1. A shaving unit for a double edge safety razor, said shaving unit comprising: a. a first flexible member including a pair of transversely extending opposite sides, each one of the first member opposite sides having a cutting edge, and a pair of spaced end tabs, each one of said tabs extending outwardly from an opposite end of said first member; b. a second flexible member including a pair of transversely extending opposite sides, each one of the second member opposite sides having a cutting edge, and a pair of spaced end tabs, each one of said tabs extending outwardly from an oppoSite end of said second member, said second member being positioned above said first member with the cutting edges of said second member being positioned upwardly and inwardly of the cutting edges of said first member; c. a transversely elongated aperture between said tabs of said first member and said second member and vertically extending through said shaving unit for locating said shaving unit in said safety razor; and d. means between said aperture and the cutting edges to one side only of said aperture for permanently connecting said first member and said second member together; e. the cutting edges to said one side of said aperture being spaced apart a predetermined distance, and the cutting edges to the other side of said aperture being spaced apart a distance less than said predetermined distance when said first and second members are in an unflexed state.
 2. The shaving unit of claim 1 further comprising flexible means between said first member and said second member for vertically spacing said second member from said first member.
 3. The shaving unit of claim 2 wherein said connecting means comprises means for bonding said spacing means to said first member and to said second member.
 4. The shaving unit of claim 3 wherein the cutting edges of said first member and said second member are parallel.
 5. The shaving unit of claim 4 wherein said first and second members are metallic members.
 6. The shaving unit of claim 5 wherein said spacing means is a metallic component.
 7. The shaving unit of claim 6 wherein said connecting means comprises a plurality of spot welds.
 8. The shaving unit of claim 6 wherein said first and second members are double cutting edge safety razor blades.
 9. The shaving unit of claim 1 wherein said connecting means comprises means for bonding said second member directly to said first member.
 10. The shaving unit of claim 9 wherein the cutting edges of said first member and said second member are parallel.
 11. The shaving unit of claim 10 wherein said first and second members are metallic members.
 12. The shaving unit of claim 11 wherein said connecting means comprises a plurality of spot welds.
 13. The shaving unit of claim 12 wherein said first and second members are double cutting edge safety razor blades.
 14. The shaving unit of claim 1 wherein said first and second members are double cutting edge safety razor blades.
 15. The shaving unit of claim 1 wherein said tabs are curved and the cutting edges to said other side of said aperture are spaced apart at least approximately said predetermined distance when said unit is seated in said double edge safety razor. 